Track-driven machines typically require a system for maintaining proper tension in the tracks. The tension in the tracks must be sufficient to provide a driving friction force between a drive wheel and the track, but may not be so large as to damage the machine components or the track.
Improved methods and systems for tensioning tracks are needed. A track may be tensioned by biasing a wheel that engages the track. Various systems have been provided for tensioning a track by biasing a wheel.
A track tensioning system for a tracked vehicle having left and right tracks includes a biasing system for simultaneously providing track tensioning to both tracks by biasing each track through a track-tensioning arc. The biasing system may include a linear force-generating system for generating a track-tensioning force. The linear force-generating system may for example be a spring or a piston and cylinder assembly. The biasing system may also include a pivoting rocker arm assembly for transmitting the track-tensioning force from the linear force-generating system to the tracks.
In another embodiment, a track tensioning system for tensioning a left and right track on a tracked vehicle includes a left track tensioning wheel arranged and configured to engage the left track, a right track tensioning wheel arranged and configured to engage the right track, a force generating system for providing a track tensioning force, and a coupling system arranged and configured to couple the left track tensioning wheel and right track tensioning wheel to the force generating system. The left track tensioning wheel may be rotatable around a left rotation axis and pivotable in a left pivot plane around a left pivot axis that is displaced from the left rotation axis. The right track tensioning wheel may be rotatable around a right rotation axis and pivotable in a right pivot plane around a right pivot axis that is displaced from the right rotation axis.
The coupling system may be arranged and configured to couple the left track tensioning wheel and right track tensioning wheel to the force generating system for transmitting the biasing force from the force generating system to the left and right track tensioning wheels for tensioning the left and right track. The coupling system may include a rocker plate that is pivotably coupled to the force generating system for balancing the tension in the left and right tracks. The rocker plate may be coupled to the force generating system with a spherical bearing. The system may also include a left wheel plate that couples the rocker plate to the left track tensioning wheel and a right wheel plate that couples the rocker plate to the right track tensioning wheel. The rocker plate may be coupled to the left wheel plate with a left spherical bearing and coupled to the right wheel plate with a right spherical bearing. The tracked vehicle may define orthogonal X, Y, and Z axes and the rocker plate may be pivotable around each of the X, Y and Z axes.
The left pivot plane and right pivot plane may be substantially parallel. The left pivot plane and right pivot plane may also be substantially vertical. The rocker plate may have a neutral position in which the rocker plate is substantially perpendicular to the left pivot plane and right pivot plane.
The force generating system may include a piston and cylinder assembly. The piston and cylinder assembly may include a first end and a second end, the second end being coupled to the rocker plate by the spherical bearing. The frame may include portions defining a pocket for receiving the first end of the piston and cylinder assembly.
The track tensioning system may also include a bolt that couples the left wheel assembly to the right wheel assembly.
In another embodiment, a track tensioning system for simultaneously tensioning left and right tracks on a tracked vehicle includes a frame, left and right wheel plate assemblies that are each coupled to the frame, a rocker plate that is coupled to the left and right wheel plate assemblies, and a cylinder assembly having a front end and a back end, the front end being pivotably coupled to the rocker plate, the back end being supported by the frame. The cylinder assembly may be actuated to bias the rocker plate and the left and right wheel plate assemblies to tension the left and right tracks. The rocker plate may pivot to balance the tension in the left and right tracks.
The left wheel plate assembly may include a left wheel that is rotatable around a left wheel rotation axis and arranged and configured to engage the left track. The left wheel plate assembly may be pivotable in a left pivot plane around a left pivot axis that is displaced from the wheel rotation axis. The right wheel plate assembly may include a right wheel that is rotatable around a wheel rotation axis and arranged and configured to engage the right track. The right wheel plate assembly may be pivotable in a right pivot plane around a right pivot axis that is displaced from the wheel rotation axis. The left pivot plane may be substantially parallel to the right pivot plane. The left and right pivot planes may be substantially vertical. The left wheel rotation axis and right wheel rotation axes may be substantially parallel to the respective left and right pivot axis. The rocker plate may have a neutral position in which the rocker plate is substantially perpendicular to the left and right wheel plate assemblies. The rocker plate may be pivotable in three dimensions relative to the cylinder assembly. The rocker plate may be coupled to the cylinder assembly with a spherical bearing. The cylinder assembly may move through a substantially vertical cylinder pivot plane. A constant pressure may be maintained in the cylinder assembly for automatically adjusting the tension in the tracks.
The left and right wheel plate assemblies may each be pivotable in three dimensions relative to the rocker plate. The left and right wheel assemblies may each be coupled to the rocker plate with a spherical bearing.
The frame may include a left supporting surface and a right supporting surface. The left wheel plate assembly may be slidably supported by the left supporting surface of the frame and the right wheel plate assembly may be slidably supported by the right supporting surface of the frame. The left wheel plate assembly may be laterally displaced a distance from the right wheel plate assembly. The left and right supporting surfaces of the frame may prevent the left and right wheel plate assemblies from moving inward out of alignment with the tracks. The rocker plate may prevent the left and right wheel plate assemblies from moving outward out of alignment with the tracks.
The left and right wheel plate assemblies may each be coupled to the rocker plate with a spherical bearing. The system may include a shaft coupled to each end of the rocker plate. Each shaft may include a body for engaging a spherical bearing and a threaded end extending outwardly beyond the spherical bearing. The system may also include a nut engaged on the threaded end of each shaft. The system may also include a bolt that couples the left plate assembly to the right plate assembly.
The left wheel assembly and right wheel assembly may each include a drive wheel that is coupled to a hydraulic drive motor. The left wheel assembly may include a drive plate, a gear system housing coupled to the drive plate, and a gear system contained within the gear system housing, the gear system being coupled to the hydraulic motor and the drive wheel. The gear system may include a planetary gear system.
The system may also include a relief valve for relieving pressure in the cylinder to permit retraction of the left and right wheel plate assemblies when the interaction of the track tensioning system with a stationary object causes a pressure spike.
In another embodiment, a method of adjusting the tension in a left and right track on a tracked vehicle includes providing a frame, a left track tensioning system arranged and configured to bias the left track through an arc for tensioning the left track, a right track tensioning system arranged and configured to bias the right track through an arc for tensioning the right track, a cylinder assembly for providing a track tensioning force, and a load coupling and balancing system for coupling the cylinder assembly to the left track tensioning system and the right track tensioning system. The load coupling and balancing system may include a rocker arm that is coupled to the left track tensioning system and the right track tensioning system. The method may further include the step of extending the cylinder assembly to increase the tension in the tracks, and retracting the cylinder assembly to decrease the tension in the tracks. The method may also include pivoting the rocker plate to balance the tension in the two tracks.
The method may also include the step of providing a constant pressure in the cylinder assembly. The constant pressure in the cylinder assembly may cause the cylinder assembly to extend in response to a reduction in tension in the tracks.
In another embodiment, a track tensioning system includes a frame having a left side and a right side, a cylinder assembly pivotably coupled to the frame, a rocker assembly coupled to the cylinder assembly with a spherical bearing, a left track interface assembly that is pivotably coupled to the left side of the frame, and a right track interface assembly that is pivotably coupled to the right side of the frame. The cylinder assembly may include a cylinder and a piston slidably disposed within the cylinder. The rocker assembly may include a rocker arm. The left track interface assembly may include a left side plate that is coupled to the rocker assembly with a spherical bearing and a left wheel that is arranged and configured to interface with a left vehicular drive track. The left wheel may be rotatably coupled to the left side plate. The right track interface assembly may include a right side plate that is coupled to the rocker assembly with a spherical bearing and a right wheel that is arranged and configured to interface with a right vehicular drive track. The right wheel may be rotatably coupled to the right side plate.
The tension in the first and second vehicular drive tracks may be adjusted by sliding the piston in the cylinder to actuate the rocker arm and pivot the first track interface assembly and second track interface assembly around the pivot axis.
The track left and right track interface assemblies may each include a drive mechanism. The drive mechanism may include a hydraulic drive motor. The track interface assembly may also include a left pivot member extending inwardly for pivotably coupling the left track interface assembly to the frame.
In another embodiment, a track tensioning system for a tracked vehicle having both a frame with left and right side members as well as left and right tracks that are both configured to translate along the ground to move the vehicle includes left and right wheel plates located substantially adjacent to a respective side member. Left and right wheels are coupled to the respective left and right wheel plates. The left and right wheels are coupled to the left and right tracks and rotate on a rotational axis so that, as the tracks translate along the ground, both wheels rotate with the tracks. For providing track tensioning to the tracks, each wheel plate pivots against the respective side member of the frame on a pivot axis that is displaced form the rotational axis. The left and right wheel plates may pivot in substantially parallel pivot planes. The substantially parallel pivot planes may be vertical. The left wheel plate may pivot around a left pivot axis and the right pivot plate may pivot around a right pivot axis. The left pivot axis and right pivot axis may be collinear. The left wheel plate and right wheel plate may be coupled together with a bolt extending along the pivot axis. The wheel plates may each be pivotably coupled to the frame with a bushing.
In another embodiment, a system for tensioning a track includes a track tensioning wheel for engaging and tensioning a track, a biasing system for providing a track tensioning force, a frame having a planar surface member that defines a pivoting plane, and a pivoting wheel plate that is coupled to the track tensioning wheel and to the biasing system. The track tensioning wheel may be rotatable around a wheel rotation axis. The pivoting wheel plate may be supported substantially against the planar surface member of the frame and may be pivotable in the pivoting plane around a pivot axis that is displaced from the wheel rotation axis. The pivoting wheel plate may slide substantially against the planar surface member of the frame as the pivoting wheel plate pivots to tension a track. The pivoting plane may be substantially vertical.
The system may include a second pivoting wheel plate and a second track tensioning wheel for engaging a second track. The frame may include a second planar surface that defines a second pivoting plane, the second pivoting wheel plate being supported against the second planar surface and being pivotable in the second pivoting plane. The second pivoting wheel plate may slide against the second planar surface of the frame as the second pivoting wheel plate pivots to tension a second track.
The system may also include a coupling system for coupling the wheel plates together. The coupling system may include a rocker arm that couples the pivoting wheel plate assemblies together. The rocker arm may pivot to balance the tension in the first and second tracks. The system may also include side plate spherical bearings that couple the wheel plate assemblies to the rocker arm.
The system may also include a pivot tube for coupling the pivoting wheel plate to the frame. The frame may include a frame tube for receiving the pivot tube, the frame tube having an inner diameter that is larger than the outer diameter of the pivot tube for rotatably supporting the pivot tube.
In another embodiment, a track tensioning system for balancing the track tension forces in left and right tracks on a tracked vehicle includes a frame, a left wheel plate assembly that is coupled to the frame, a right wheel plate assembly that is coupled to the frame, and a rocker arm member that is coupled to the frame and to the left and right wheel plate assemblies. The left wheel plate assembly may include a left wheel that is rotatable around a left wheel rotation axis, the left wheel plate assembly being pivotable in a left pivot plane around a left pivot axis that is displaced from the left wheel rotation axis. The left wheel plate assembly may be arranged and configured to engage the left track. The right wheel plate assembly may include a right wheel that is rotatable around a right wheel rotation axis, the right wheel plate assembly being pivotable in a right pivot plane around a right pivot axis that is displaced from the right wheel rotation axis. The right wheel plate assembly may be arranged and configured to engage the right track. The rocker arm member may transfer track tension forces between the left track and the right track, and the left wheel plate assembly and right wheel plate assembly may pivot to balance the tension in the tracks.
The left pivot plane may be substantially parallel to the right pivot plane. The left and right pivot planes may be substantially vertical. The rocker arm member may have a neutral position in which the rocker arm member is substantially perpendicular to the left and right wheel plate assemblies. The left wheel rotation axis may be substantially parallel to the left pivot axis.
The left and right wheel plate assemblies may each be pivotable in three dimensions relative to the rocker arm member and may be coupled to the rocker arm member with a spherical bearing. The rocker arm member may be pivotable in three dimensions relative to the frame and may be coupled to the frame with a rocker spherical bearing. The rocker spherical bearing may be coupled to a linkage which is coupled to the frame.
The frame may include a left supporting surface and a right supporting surface. The left wheel plate assembly may be slidably supported by the left supporting surface of the frame and the right wheel plate assembly may be slidably supported by the right supporting surface of the frame.
The left wheel plate assembly may be laterally displaced a distance from the right wheel plate assembly. The left and right supporting surfaces of the frame may prevent the left and right wheel plate assemblies from moving inward out of alignment with the tracks. The rocker arm member may prevent the left and right wheel plate assemblies from moving outward out of alignment with the tracks. A bolt may also be provided to couples the left plate assembly to the right plate assembly.
The left and right wheel plate assemblies may each be coupled to the rocker arm member with a spherical bearing. A shaft may be coupled to each end of the rocker arm member. Each shaft may include a body for engaging a spherical bearing and a threaded end extending outwardly beyond the spherical bearing. A nut may be engaged on the threaded end of each shaft.
The left wheel assembly and right wheel assembly may each include a drive wheel that is coupled to a hydraulic drive motor. The left wheel assembly may include a drive plate, a gear system housing coupled to the drive plate, and a gear system contained within the gear system housing, the gear system being coupled to the hydraulic motor and the drive wheel. The gear system may include a planetary gear system.
In another embodiment, a rocker arm assembly for a track tensioning system on the tracked vehicle includes a rocker arm member that is coupled to the frame and is pivotable around the X, Y, and Z axes defined by a vehicle frame. A tracked vehicle has a left and a right track, a left and a right wheel assembly each engaging a respective track, and a frame defining orthogonal X, Y, and Z axes. The rocker arm member may also be coupled to the left and right wheel assemblies, so that the rocker arm member may transmit track tensioning forces to the left and right wheel assemblies for tensioning the tracks. The rocker arm assembly may also include a spherical bearing for coupling the rocker arm member to the frame. Left and right spherical bearings may also be used for coupling the rocker arm member to respective left and right wheel assemblies. The rocker arm member may include a narrowed center portion for coupling the rocker arm to a linkage member. The rocker arm assembly may be adapted and configured for coupling to a piston and cylinder assembly.
In another embodiment, a track tensioning system for a tracked vehicle having left and right tracks includes a constant-force biasing system for automatically and simultaneously providing track tensioning to both tracks by biasing each track through a track-tensioning arc. The track tensioning system may include a linear force-generating system for generating a track-tensioning force. The linear force-generating system may include a spring. Alternatively, the linear force-generating system may include a piston and cylinder assembly, and a constant pressure may be provided in the piston and cylinder assembly. The constant force biasing system may also include a pivoting rocker assembly for transmitting the track-tensing force from the linear force-generating system to the tracks. The pivoting rocker assembly may be pivotable around orthogonal X, Y, and Z axes. This coupling arrangement may permit the rocker arm assembly to be pivoted such that the left track is biased through a degree of displacement through the track tensioning arc and the right track is biased through a degree of displacement through the track tensioning arc that is different from the degree of displacement of the left track. To couple the biasing system to the tracks, the rocker arm assembly may be coupled to a left track tensioning wheel and a right track tensioning wheel that are coupled to a respective left and right track.
In another embodiment, a tracked vehicle has left and right tracks and a balanced track tensioning system. The balanced track tensioning system includes a biasing system for providing balanced track tensioning to both tracks by independently biasing each track through a track-tensioning arc. The biasing system may include a pivoting rocker assembly for transmitting a track-tensing force to the tracks. The rocker assembly may be pivotable around X, Y, and Z axes that are defined by the balanced track tensioning system. The rocker arm assembly may be pivoted such that the left track is biased through a degree of displacement through the track tensioning arc and the right track is biased through a degree of displacement through the track tensioning arc that is different from the degree of displacement of the left track, wherein the left track and right track may be biased independently to balance the tension in the left and right tracks. For coupling the biasing system to the tracks, the rocker arm assembly may be coupled to a left track tensioning wheel and a right track tensioning wheel which are coupled to a respective left and right track.
In another embodiment, a tracked vehicle has a left, a right track and a track tensioning relief system. The track tensioning relief system may include a left and right track tensioning system each configured to tension a respective track, a force-generating system for providing a track-tensioning force, a coupling system for coupling the force-generating system to the left and right track tensioning systems, and a force-limiting system for restricting the amount of force provided by the force-generating system. The force-generating system may include a hydraulic piston and cylinder assembly. The force-limiting system may include a hydraulic pressure relief valve. The left track tensioning system may include a frame and a track tensioning wheel that is rotatably coupled to the frame to rotate around a rotation axis. The track tensioning wheel may be pivotably coupled to the frame to pivot around a pivot axis that is displaced from the rotation axis. Each track tensioning wheel may be configured to engage the a respective track, so that pivoting the left track tensioning wheel around the pivot axis tensions the left track.
Another embodiment includes a cylinder coupling system for coupling a hydraulic cylinder to a track tensioning system. A track tensioning system for a track vehicle may include a hydraulic cylinder for generating a track-tensioning force. A cylinder coupling system for coupling the cylinder to the track tensioning system includes a cylinder endcap that is coupled to the hydraulic cylinder assembly, a linkage arm having orthogonal X, Y, and Z axes, a spherical bearing that is coupled to the linkage arm, and a shaft that is coupled to the spherical bearing and the cylinder endcap. The cylinder endcap may have portions defining a slot for receiving the linkage arm. The cylinder endcap may also have portions defining a bore for receiving the shaft. The cylinder coupling system may permit the linkage arm to pivot around each of the X, Y, and Z axes.